fp_class(3C)							  fp_class(3C)

NAME    [Toc]    [Back]

     fp_class, fp_class_d, fp_class_f -	classes	of IEEE	floating-point values

     fp_class_l	- classes of long double floating-point	values

SYNOPSIS    [Toc]    [Back]

     #include <fp_class.h>

     int fp_class_d(double x);

     int fp_class_f(float x);

     int fp_class_l(long double	x);

DESCRIPTION    [Toc]    [Back]

     (Note that	the long double	routines are only valid	for the	MIPSpro
     compilers.)  Long double function fp_class_l has been renamed to be
     compliant with the	ANSI-C standard, however to be backward	compatible, it
     may still be called with the name fp_class_q.

     These routines are	used to	determine the class of IEEE or long double
     floating-point values.  They return one of	the constants in the file
     <fp_class.h> and never cause an exception even for	signaling NaN's.
     These routines are	to implement the recommended function class(x) in the
     appendix of the IEEE 754-1985 standard for	binary floating-point
     arithmetic.

     The constants in <fp_class.h> refer to the	following classes of values:

     Constant	    Class
     FP_SNAN	    Signaling NaN (Not-a-Number)
     FP_QNAN	    Quiet NaN (Not-a-Number)
     FP_POS_INF	    +oo	(positive infinity)
     FP_NEG_INF	    -oo	(negative infinity)
     FP_POS_NORM    positive normalized	non-zero
     FP_NEG_NORM    negative normalized	non-zero
     FP_POS_DENORM  positive denormalized
     FP_NEG_DENORM  negative denormalized
     FP_POS_ZERO    +0.0 (positive zero)
     FP_NEG_ZERO    -0.0 (negative zero)

     Note that these functions are distinct from the SVR4 function fpclass
     (see isnan(3C)).

SEE ALSO    [Toc]    [Back]

     isnan(3C).
     ANSI/IEEE Std 754-1985, IEEE Standard for Binary Floating-	Point
     Arithmetic

     In	the case of long doubles, non-zero numbers less	than 2**-916 in
     absolute value are	classified as denormalized, since one of the numbers
     used in their representation may be a denormal double.


									PPPPaaaaggggeeee 1111